Well I replaced the thermostat and it still does the same thing. What is happening is the coolant gets hot and then it goes into the overflow reservoir. I let it cool down and I open the radiator up and its low so then I fill it backup and then a day or two later the overflow reservoir is fill to the top. So I dump it out and start all over. While I was doing this I looked at the radiator cap and it the rubber piece that goes around the top of the cap was split in half. So we will see if thats the problem.